SD2 (Sound Designer II) is Digidesign's classic Pro Tools container — still the default export of many legacy studio sessions and Mac-era sample libraries.
Typical use: Convert SD2 sessions to WAV or FLAC.
About the SD2 format
HCOM is the Sound Tools compressor format from the late 1980s Mac — FIR-decimated delta-modulation samples that almost nothing modern reads.
ffmpeg decodes it natively inside your browser — the audio track is re-encoded to your chosen format with nothing ever uploaded.
Strengths
- ✓ Decoded natively by ffmpeg
- ✓ Runs entirely in your browser
- ✓ Free, private, no watermarks
Limitations
- ✗ Legacy niche format
- ✗ Modern tools rarely open it
- ✗ Keep the original for archival round-trips
- Structure
- Sound Designer II container
- Compatibility
- ffmpeg, archive tools
- Best for
- Rescuing legacy audio
Convert SD2 to…
27 direct directions plus 18 workflows, sorted A–Z; 🔥 marks popular targets.
Frequently asked questions
What is a SD2 file?
SD2 (Sound Designer II) is Digidesign's classic Pro Tools container — still the default export of many legacy studio sessions and Mac-era sample libraries.
How do I convert SD2 files online?
Pick a target format from the "Convert SD2 to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert SD2 files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can SD2 convert to?
This page lists all 45 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.